"We have been concerned about events in Hong Kong and are closely monitoring developments," a spokeswoman for the EU's diplomatic service said.
"In the light of the ongoing demonstrations, we welcome the restraint shown by both sides. We urge all sides to continue to exercise this restraint."
Hong Kong authorities urged swelling crowds of demonstrators today to disperse "as soon as possible" and were seen unloading boxes of tear gas and rubber bullets.
The EU encouraged "all parties to work in a spirit of compromise for a constructive solution" within the framework of the "one country two systems" formula, at the heart of the handover agreement between the Chinese and British authorities enshrining a capitalist system for Hong Kong for 50 years until 2047.